Many tissue products, such as toilet paper and paper towels, are typically formed into large supply rolls after being manufactured. After the supply rolls are formed, the rolls are rewound into smaller sized rolls, which are generally more useful for commercial purposes. For example, in many conventional processes, the tissue product is wound onto a hollow cylindrical core made of paper stock during a winding and converting operation.
Once formed into smaller rolls, the rolls of material are then typically fed to a packaging line and packaged in groups such as by being encased in a plastic film. The packaged groups are then placed in boxes or poly bundles and shipped to customers.
In one embodiment, for example, the packaging equipment may include an in-feed conveyor and a sorter for placing the rolls of material into groups of a desired size. The groups are then fed to a forming shoulder where the groups are placed in a tube formed from a plastic packaging film. The film is longitudinally sealed and advanced with the entrained product to a separating apparatus. At the separating apparatus, the tube is periodically severed into individual packages. The open ends of the packages are then folded and sealed and the packages are stacked in boxes. One embodiment of an exemplary packaging line as described above is disclosed in U.S. Pat. No. 5,195,300, which is incorporated herein by reference.
As the rolls of material are packaged, the rolls are typically periodically compressed in order to control the movement of the packages and their processing in the wrapper in order to form properly grouped and separated packages with good tightness.
One problem encountered in conventional packaging equipment, however, is that the equipment is not capable of automatically adjusting to variations in the size and firmness of the product. For example, the product size and firmness can change due to inconsistencies during production and converting of the rolls. Size changes also occur as different products are being packaged. Instead of allowing for size and firmness variations, packaging equipment typically runs at a fixed position. Thus, size and firmness changes of the product cause changes in the amount of compressive force applied to the product allowing for wrapper plug-ups and roll misfeeds. Such problem areas can cause machine downtime and production inefficiencies. Further, in order to implement a grade change, many packaging lines must be shut down and adjusted manually for an extended period of time in order to accommodate the new products.